Abstract
Inheritance of fruit cracking of Japanese persimmon (Diospyros kaki Thunb.) was investigated using data collected over 30 years. The cracking which occurs at the calyx end and the stylar end is referred to as “Hetasuki”and “Kachorekka”, respectively.
Varieties of PCNA (pollination constant non-astringent) were most likely to cause “Hetasuki” and/or “Kachorekka” cracking. The crosses between varieties showing no cracking resulted in the progenies with little or no cracking. However, crosses between varieties showing cracking resulted in wide range of segregation from non- to severe cracking. Similar results were obtained from crosses between varieties with and without cracking. Therefore, the heredity of the traits producing non-cracking fruit seems to be dependent on the homozygosity of the genes involved.
Negative correlations were found between the percentage of progenies without cracking and the mean values of cracking of their parents; the correlation coefficients were -0.54** to -0.64** for “Hetasuki” and -0.68** to -0.76** for “Kachorekka.”
The PCNA varieties which had been selected under breeding programs at Fruit Tree Research Station and whose traits had been examined for regional adaptability at many locations, also frequently exhibited “Hetasuki”and “Kachorekka” cracking.
It is important to eliminate the progenies with severe cracking at early stages of selection, which will make the breeding of Japanese persimmon, notably of PCNA varieties, more efficient.
